1. Field of the Invention
The present invention relates to a height adjustable accessory structure. In a preferred form shown, a C-shaped ring is disposed in an engaging sleeve including a main sleeve body and an assistant sleeve body engaged with each other for allowing insertion and positioning of an engaging rod with a plurality of engaging portions. The bottom of the engaging rod includes a tightening section and an engaging member whose size is between the outer diameter and the inner diameter of the engaging sleeve. The tightening section allows free deformation of the elastic hooks at the bottom of the engaging sleeve, thus allowing the elastic hooks to successfully pass through the sleeve and enabling the elastic hooks to be positioned below the engaging sleeve after inserting through the sleeve. After the engaging sleeve is engaged with the sleeve, the engaging member can be stopped against the elastic hooks, thus preventing the engaging rod from being pulled away from the engaging sleeve and avoiding the problem of unexpected disengagement of the engaging rod during operation.
2. Description of the Prior Art
Height adjustable structure is a structure that can offer the height adjustable function. This height adjustable design makes mass produced products suitable for different users with different body forms. Therefore, height adjustable structure is very important.
In a conventional height adjustable accessory structure with an engaging rod and an engaging sleeve, the engaging sleeve is inserted in a sleeve so as to allow the engaging rod to be inserted into the engaging sleeve. A, C-shaped ring is located inside the engaging sleeve to engage with the engaging section of the engaging rod to carry out step adjustment (in a conventional engaging sleeve, there is also an elastic piece made by plastic molding to offer a clamping force, but the plastic material is likely to lose elasticity and become brittle, so relevant discussions will be omitted here.). The conventional height adjustable accessory structure is easy to operate, but its cost is high, since the C-shaped ring of the engaging sleeve is difficult to manufacture, so that it can be accepted by the general manufacturer. Since an annular groove must be preformed in the inner wall of the engaging sleeve and the C-shaped ring will be positioned with the annular groove after elastic deformation, the manufacturing process is very difficult, and the C-shaped ring is likely to disengage or be damaged during the assembly process. Additionally, lacking any structure between the engaging rod and the engaging sleeve for preventing disengagement, the whole rod can be pulled out by an improper force, thus causing inconveniences in operation.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.